1. Field of the Invention
The present invention relates to a magnetic transfer method and apparatus, by which a magnetic layer of a magnetic transfer master medium, on which a pattern has been formed for transferring data, and a magnetic layer of a slave medium are brought into close contact to form a conjoined body, and applying a transfer magnetic field to said conjoined body so as to magnetically transfer the data borne by the patterned magnetic layer of the master medium to the magnetic layer of the slave medium.
2. Description of the Related Art
Generally speaking, with regard to magnetic storage mediums, there is a demand for increased storage capacity and low cost. Further desired are so-called high-speed access mediums, which are capable of advantageously reading out the data of a desired location in a short time. Examples of these mediums include the high speed magnetic recording mediums (magnetic disk mediums) utilized in hard disk apparatuses and floppy disk apparatuses. So-called tracking servo technology, wherein the magnetic head accurately scans a narrow width track to reproduce signals with a high S/N ratio, plays a substantial role in attaining the high storage capacity thereof. A servo signal, address data signal, replay clock signal, etc., used for tracking are “preformatted” within a certain interval occurring in one rotation of the disk, that is, recorded on the disk in advance.
Magnetic transfer methods realizing accurate and efficient preformatting, wherein the data such as a servo signal or the like borne on a master medium is magnetically transferred therefrom to a magnetic recording medium, have been proposed in, for example, Japanese Unexamined Patent Publication Nos. 63(1988)-183623, 10(1998)-40544, and 10(1998)-269566.
According to these magnetic transfer technologies: a master medium having an uneven pattern corresponding to the data that is to be transferred to a magnetic recording medium (a slave medium) is prepared; this master medium is brought into close contact with a slave medium to form a conjoined body; and a transfer magnetic field is applied thereto, whereby a magnetic pattern corresponding to the data (e.g., a servo signal) borne on the master medium is transferred to the slave medium. Therefore, preformatting can be statically performed without changing the relative positions of the master medium and the slave medium. Not only is it possible to perform an accurate recording of the preformat data, it becomes possible to advantageously do so in an extremely short time.
However, as to the magnetic recording medium, two possibilities are horizontal magnetic recording mediums provided with a good magnetization axis in the horizontal direction in relation to the surface of the magnetic layer thereof, and vertical magnetic recording mediums provided with a good magnetization axis in the vertical direction in relation to the surface of the magnetic layer thereof; however, in current practice, horizontal magnetic recording mediums are generally employed, and the magnetic transfer technology described above has also been developed focusing mainly on the horizontal magnetic recording mediums as the magnetic recording medium of choice. On the other hand, if a vertical magnetic recording medium is employed, an even greater increase in data storage capacity can be expected in comparison to the horizontal magnetic recording mediums.
For cases in which a magnetic transfer is performed on a vertical magnetic recording medium, a magnetic field must be applied in the perpendicular direction with respect to the surface of the magnetic layer thereof; wherein the optimal conditions differ with respect to cases in which a magnetic transfer is performed on a horizontal magnetic recording medium.